UniWiki:Manual of Style/Dates and numbers
This page guides the presentation of numbers, dates, times, measurements, currencies and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important within an article. The goal is to make the whole UniWiki easier and more intuitive to use.
Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor.
General notes
Quotations, titles, etc.
Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they employ formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via [bracketed interpolation], article text, or footnotes.
- It is acceptable to change other date formats in the same article to provide consistency, so long as those changes would otherwise be acceptable.
Non-breaking spaces
Guidance on the use of non-breaking spaces ("hard spaces") –
,  
– is given in some sections below. Not all situations in which hard spaces may be appropriate are described. For further information, see Wikipedia:Manual of Style § Controlling line breaks and Wikipedia:Line-break handling.
Chronological items
Statements likely to become outdated
Except on pages updated regularly, terms such as now, currently, to date, so far, soon, and recently should usually be avoided in favor of phrases such as during the 1990s, since 2010, and in August 1969. For current and future events, use phrases like as of December 2024 or since the beginning of 2024 to signal the time-dependence of the information.
However, do not replace since the beginning of 2005 with as of 2005 because some information (the beginning of 2005) would be lost.
Relative-time expressions are acceptable for very long periods, such as geological epochs: Humans diverged from other primates long ago, but only recently developed state legislatures.
Time of day
Context determines whether the 12- or 24-hour clock is used; in both, colons separate hours, minutes and seconds (e.g. 1:38:09 pm or 13:38:09).
- 12-hour clock times end with dotted or undotted lower-case a.m. or p.m., or xtn|am or pm, preceded by a non-breaking space, e.g. 2:30 p.m. or 2:30 pm (markup:
2:30 p.m.
or2:30 pm
), not 2:30p.m. or 2:30pm. Hours should not have a leading zero (e.g. 2:30 p.m., not 02:30 p.m.). Usually, use noon and midnight rather than 12 pm and 12 am; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context. - 24-hour clock times have no a.m., p.m., noon or midnight suffix. Hours under 10 should have a leading zero (e.g. 08:15). The time 00:00 refers to midnight at the start of a date, 12:00 to noon, and 24:00 to midnight at the end of a date, but 24 should not be used for the first hour of the next day (e.g. use 00:10 for ten minutes after midnight, not 24:10).
The numerical elements of times-of-day are figures (12:45 p.m.) rather than words (twelve forty-five p.m.) though conventional terms such as noon and midnight are acceptable (taking care, with the latter, to avoid possible date ambiguity in constructions such as midnight on July 17).
Time zones
Give dates and times appropriate to the time zone where an event took place. For example, the date of the attack on Pearl Harbor should be December 7, 1941 (Hawaii time/date). Give priority to the place at which the event had its most significant effects; for example, if a hacker based in China attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases the best solution may be to add the date and time in Coordinated Universal Time (UTC). For example:
- • 8 p.m. Eastern Standard Time on January 15, 2001 (01:00 UTC, January 16)
Alternatively, include just the UTC offset:
- • 21:00 British Summer Time (UTC+1) on 27 July 2012
Rarely, the time zone in which a historical event took place has since changed; for example, China to 1949 was divided into five time zones, whereas all of modern China is UTC+8. Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960; Universal Time (UT) is the appropriate term for the mean time at the prime meridian (Greenwich) when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ.
Dates, months and years
Formats
General use | Only where brevity is helpful (refs, tables, infoboxes, etc.) |
Comments |
---|---|---|
2 August 2001 | 2 Aug 2001 | |
August 2, 2001 | Aug 2, 2001 | A comma follows the year unless followed by other punctuation:[1] * The weather on March 12, 2005, was clear and warm * Everyone remembers July 21, 1969 - when man first landed on the Moon |
2 August | 2 Aug | Omit year only where there is no risk of ambiguity: * The 2012 London Olympics ran from 25 July to 12 August * January 1 is New Year's Day |
August 2 | Aug 2 | |
No equivalent for general use | 2001-08-02 | Use yyyy-mm-dd format only with Gregorian dates from 1583 onward.[2] |
August 2001 | Aug 2001 |
- Dates should be linked only when they are germane to the subject.
- For issues related to dates in sortable tables, see Wikipedia:Date sorting problems.
- Phrases such as Fourth of July (or July Fourth, but not July 4th), Cinco de Mayo, Seventh of March Speech and Sete de Setembro are proper names, to which rules for dates do not apply (Any decent Fourth of July celebration includes fireworks).
Unacceptable | Acceptable | Comments |
---|---|---|
Aug. 2 | Aug 2 | Do not add a dot to the day or to an abbreviated month |
9. June | 9 June or June 9 | |
9 june june 9 |
Months are capitalized | |
9th June June 9th the 9th of June |
Do not use ordinals (1st, 2nd, 3rd, etc.) | |
09 June June 09 |
Do not "zero-pad" month or day, except in all-numeric (yyyy-mm-dd) format | |
2007-4-15 | 2007-04-15 | |
2007/04/15 | Do not use separators other than hyphen | |
07-04-15 | Do not abbreviate year to two digits | |
15-04-2007 04-15-2007 |
Do not use dd-mm-yyyy, mm-dd-yyyy or yyyy-dd-mm formats, as they are ambiguous for some dates[3] | |
7/2001 7-2001 07-2001 2001-07 2001 July July of 2001 |
July 2001 | Do not use these formats. |
July, 2001
|
No comma between month and year | |
3 July, 2001 | 3 July 2001 | |
July 3 2001 | July 3, 2001 | Comma required between day and year |
the '97 elections the 97 elections |
the 1997 elections | Do not abbreviate year |
Two thousand one | 2001 | Years and days of the month are not normally written in words |
the first of May May the first |
May 1 or 1 May | |
June 0622 | June 622 | Do not zero-pad years |
sold in the year 1995 | sold in 1995 | Use "in the year" only where needed for clarity (About 1800 ships arrived in the year 1801) |
Consistency
Dates in article body text should all use the same format: She fell ill on 25 June 2005 and died on 28 June, but not She fell ill on 25 June 2005 and died on June 28.
Retaining existing format
- If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page.
- The date format chosen by the first major contributor in the early stages of an article should continue to be used, unless there is reason to change it based on strong national ties to the topic or consensus on the article's talk page.
- Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".
Gregorian and New Eden calendars
Dates on the UniWiki must be given in the appropriate calendar based on the context of the date or event they are associated with. A date can be given in the Gregorian calendar, the New Eden calendar, or both, as described below. For example, an article on the early Amarr Empire will only give dates in the New Eden calendar, while an article about the Purity of the Throne event may give dates in both calendars.
- Real-world events are dated using the Gregorian calendar.
- In-game events that correspond to real-world dates (such as the Yoiul Festival 2016) or that are the result of player actions are dated using the New Eden calendar when discussing the event in an in-universe context, and using the Gregorian calendar when discussing the event in a real-world or meta context.
- All other in-game events or lore concepts are dated using the New Eden calendar.
Ranges
- Use a dash, or a word such as from or between, but not both: from 1881 to 1886 (not from 1881–1886); between June 1 and July 3 (not between June 1 - July 3)
- A simple year–year range is written using an en dash (
–
) not a hyphen or slash; this dash is usually unspaced (that is, with no space on either side); and the range's end year is usually given in full:
- • 1881–1886; 1881–1992 (not 1881–86; 1881 - 1992)
- Markup:
1881{{ndash}}1886
or1881–1886
- Two-digit ending years (1881–82, but never 1881–882 or 1881–2) may be used in the case of two consecutive years; in infoboxes and tables where space is limited (using a single format consistently in any given table column); or in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.
- The slash notation (2005/2006) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
- Markup:
- Other "simple" ranges use an unspaced en dash as well:
- day–day: 5–7 January 1979; January 5–7, 1979; elections were held March 5–8
- month–month: the 1940 peak period was May–July; the peak period was May–July 1940; (but the peak period was May 1940 - July 1940 uses a spaced en dash; see below.
- If at least one of the items on either side of the en dash contains a space, then a spaced en dash (
{{snd}}
) is used:
- between specific dates in different months: They travelled June 3 - August 18, 1952; They travelled 3 June - 18 August 1952
- between dates in different years:
- Charles Robert Darwin (12 February 1809 - 19 April 1882) was an English naturalist ...
- Markup:
12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882
or12 February 1809 – 19 April 1882
- Abraham Lincoln (February 12, 1809 - April 15, 1865) was the 16th President of ...
- between months in different years: The exception was in force August 1892 - January 1903; The Ghent Incursion (March 1822 - January 1, 1823) was ended by the New Year's Treaty
- Where circa or other modifiers are used: reigned c. 1393 - 1414 See § Uncertain, incomplete, or approximate dates, below.
- Constructions such as 1982–present (with unspaced ndash), January 1, 2011 - present (spaced ndash), or January 2011 - present (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose (see § Statements likely to become outdated). In tables and infoboxes where space is limited, pres. may be used (1982–pres.). Do not use incomplete-looking constructions such as 1982– and 1982–... .
- For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981 - ) or (born on September 26, 1981).
- Do not use
*
to indicate born; useb.
only where space is limited e.g. tables and infoboxes; use eitherborn
orb.
consistently in any given table column.
- Where birthdate is unknown: John Smith (died May 1, 1622) ... or John Smith (died 1622) ...
- Do not use
†
to indicate died; used.
only where space is limited, with consistency within any given table column.
- An overnight period may be expressed using a slash between two contiguous dates: the night raids of 30/31 May 1942 or raids of 31 May / 1 June 1942.
- Or use an en dash: (unspaced) raids of 30–31 May 1942; (spaced) raids of 31 May - 1 June 1942.
Uncertain, incomplete, or approximate dates
- To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form c. 1291 is preferred over circa, ca, ca., approximately, or approx.:
- • At the birth of Roger Bacon (c. 1214) ...
- Where both endpoints of a range are approximate, c. should appear before each date:
- • Dionysius Exiguus (c. 470 - c. 540) ... (not Dionysius Exiguus (c. 470 - 540) ...)
- • Rameses III (reigned c. 1180 – c. 1150 BCE) ... (not Rameses III (reigned c. 1180 - 1150 BCE) ...)
- When a date is known to be either of two years (e.g. from a regnal or AH year conversion, or a known age at death):
- • Anne Smith (born 1912 or 1913; died 2013) ...
- Other forms of uncertainty should be expressed in words, either in article text or in a footnote: April 14, 1224 (unattested date). Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty.
- Ranges in which c., after, fl. or similar forms appear—whether on one or both sides—employ a spaced endash (
-
) and ideally a nonbreaking space should follow very short modifiers such as c. and fl.. Markup:1896 - after 1954
Other
Days of the week
- Days of the week are capitalized (Sunday, Wednesday).
Seasons
- Seasons are uncapitalized (a hot summer) except when personified: Old Man Winter's bleak greys relent as Spring begins to show her colors.
- All seasons used should refer to seasons in the northern hemisphere, as that is where CCP is located, and is thus the reference point for game development, patch releases, and other events.
- In the rare case where an article references seasons in relation to a specific country or region not in the northern hemisphere, the appropriate season for that location may be used.
Numbers
Numbers as figures or words
See
also information on specific situations, elsewhere in this guideline.
Generally, in article text:
- Integers from zero to nine are spelled out in words.
- Integers greater than nine expressible in one or two words may be expressed either in numerals or in words (16 or sixteen, 84 or eighty-four, 200 or two hundred). Numbers between 21 and 99 are hyphenated (including when part of a larger number): fifty-six or fifty-six thousand but five hundred or five thousand.
- Other numbers are given in numerals (3.75, 544) or in forms such as 21 million. Markup:
21{{nbsp}}million
- "billion" and "trillion" are understood to represent their short-scale values of 109 (1,000,000,000) and 1012 (1,000,000,000,000), respectively. Keep this in mind when using material from non-English sources.
- M (unspaced) or bn (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (She received £70 million and her son £10M).
- SI prefixes and symbols, such as mega- (M), giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts (of the population of 1.3G people, 300 megadeaths would be expected).
Notes and exceptions:
- In tables and infoboxes, quantities are expressed in figures (Years in office: 5); but numbers within a table's explanatory text and comments follow the general rule.
- Numbers in mathematical formulae are never spelled out (3 < π < 22/7, not three < π < 22 sevenths).
- Comparable quantities should be all spelled out or all in figures:
- • five cats and thirty-two dogs, not five cats and 32 dogs
- • 86 men and 103 women, not eighty-six men and 103 women
- • There were 3 winners and 206 losers, even though 3 would normally be given as three; or Three won and two hundred six lost (or two hundred and six in British English), even though two hundred six would normally be given as 206); but not There were three winners and 206 losers.
- But adjacent quantities not comparable should usually be in different formats: twelve 90-minute volumes or 12 ninety-minute volumes, not 12 90-minute volumes or twelve ninety-minute volumes.
- Avoid awkward juxtapositions: On February 25, 2011, twenty-one more were chosen, not On February 25, 2011, 21 more were chosen.
- Personal ages are typically stated in figures (8-year-old child) except for large, approximate values (69-million-year-old fossil).
- Sometimes figures and words carry different meanings; for example Every locker except one was searched implies there is a single exception (without specifying which), while Every locker except 1 was searched means that only locker number 1 was not searched.
- Proper names, technical terms, and the like are never altered: Seven Samurai; The Sixth Sense; 5 Channel Street; Channel 5; Chanel No. 5; Fourth Estate; The Third Man; Second Judicial District; First Amendment; Zero Hour!; Less Than Zero
- Avoid beginning a sentence with figures:
- • Not There were many matches. 23 ended in a draw,
- but There were many matches; 23 ended in a draw or There were many matches. Twenty-three ended in a draw.
- • Not 1945 and 1950 saw crucial elections (nor Nineteen forty-five and 1950 saw crucial elections - because comparable numbers should be both written in words or both in figures) but The elections of 1945 and 1950 were crucial.
- Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence (1-Naphthylamine is typically synthesized via the Feldenshlager–Glockenspiel process) although this can usually be avoided by rewording (Feldenshlager–Glockenspiel is the process typically used in the synthesis of 1-naphthylamine).
Ordinals
- Ordinal suffixes (-st, -nd, -rd, -th) are not superscripted (123rd and 496th, not 123rd nor 496th).
- For guidance on choosing between e.g. 15th and fifteenth, see § Numbers as figures or words.
- Regnal numbers are normally written with Roman numerals (without suffix, e.g. Elizabeth II not Elizabeth IInd).
- Do not use a dot (.) or the ordinal mark (º) to indicate ordinals.
Singular versus plural
- Nouns following simple fractions are singular (He took 1⁄4 dose; net change in score was −1⁄2 point; 3⁄2 dose).
- Nouns following mixed numbers are plural (suicide victim knew even 11⁄2 doses could be fatal; continued another 43⁄4 miles).
- Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points; 365.25 days; paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour; increased by 1 point but net change +1 points; net change −1 points; net change 1.0 points).
- The same rules apply to numbers given in words (one dose; one and one-half doses; zero dollars; net change negative one points).
Fractions and ratios
- Spelled-out fractions are hyphenated: seven-eighths.
- Where numerator and denominator can each be expressed in one word, a fraction is usually spelled out (e.g. a two-thirds majority; moved one-quarter mile); use figures if a fraction appears with a symbol (e.g. 1⁄4 mi - markup:
<sup>1</sup>⁄<sub>4</sub> mi
, not a quarter of a mi or one-quarter mi). - Mixed numbers are usually given in figures, unspaced (not Fellini's film 8 1⁄2 or 8-1⁄2 but Fellini's film 81⁄2 - markup:
8<sup>1</sup>⁄<sub>2</sub>
). In any case the integer and fractional parts should be consistent (not nine and 1⁄2). - Metric (SI) measurements generally use decimals, not fractions (5.25 mm, not 51⁄4 mm).
- Do not use special characters such as "½" (deprecated markup:
or½
).½
- Ordinal suffixes such as -th should not be used with fractions expressed in figures (not each US state has 1/50th of the Senate's votes; 1/8th mile, but one-fiftieth of the Senate's votes; 1/8 mile; one-eighth mile).
- Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and to: favored by a 3:1 ratio or a three-to-one ratio, but not a 3/1 ratio or a 3–1 ratio. Use a "spaced" colon when a decimal point is present (a 3.5 : 1 ratio - markup:
a 3.5 : 1 ratio
). Do not use the colon form where units are involved (dissolve using a 3 ml:1 g ratio)—instead see ratios section of table at § Unit names and symbols, below.
Decimals
- A period/full point (
.
), never a comma, is used as the decimal point (6.57, not 6,57). - Numbers between −1 and +1 require a leading zero (0.02, not .02); exceptions are sporting performance averages (.430 batting average) and commonly used terms such as .22 caliber.
- Indicate repeating digits with an overbar e.g.
14.31<span style="text-decoration:overline">28</span>
gives 14.3128. (Consider explaining this notation on first use.) Do not write e.g. 14.31(28) because it resembles notations for § Uncertainty and rounding.
====Grouping
of digits====
- Digits should be grouped and separated by commas, (never a period/full point).
- Grouping with commas
- Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. 12,200, 255,200 km, 8,274,527th, 1⁄86,400).
- Numbers with exactly four digits left of the decimal point may optionally be grouped (either 1,250 or 1250), provided that this is consistent within each article.
- When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string).
- Delimiting style should be consistent throughout a given article.
- Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
- However, grouping by threes and fives may coexist.
- An exception is made for four-digit page numbers or four-digit calendar years. These should never be grouped (not sailed in 1,492, though dynasty collapsed around 10,400 BC).
Percentages
- In the body of non-scientific/non-technical articles, percent (American English) or per cent (British English) are commonly used: 10 percent; ten percent; 4.5 per cent. Ranges are written ten to twelve per cent or ten to twelve percent, not ten–twelve per cent or ten to twelve %.
- In the body of scientific/technical articles, and in tables and infoboxes of any article, the symbol
%
(unspaced) is more common: 71%, not 71 % or three %. Ranges: 10–12%, not 10%–12% or 10 to 12%. - When expressing the difference between two percentages, do not confuse a percentage change with a change in percentage points.
Scientific notation
- Scientific notation always has a single nonzero digit to the left of the point: not 60.22 × 1022, but 6.022 × 1023.
- In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. × 107 once in the column header, and omitting it in the individual entries. (Markup:
× 10<sup>7</sup>
) - The number of digits indicates the precision. For example, 5 × 103 means rounded to the nearest thousand; 5.0 × 103 to the nearest hundred; 5.00 × 103 to the nearest ten; and 5.000 × 103 to the nearest unit.
Uncertainty and rounding
- Where explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, it may be written in various ways:
- • (1.534 ± 0.035) × 1023 m
- • 12.34 m2 ± 5% (not used with scientific notation)
- • 1.604(48) × 10−4 J (equivalent to (1.604 ± 0.048) × 10−4 J)[4]
- • Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent
- Where explicit uncertainty is unavailable (or is unimportant for the article's purposes) round to an appropriate number of significant digits; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
- • The speed of light is defined to be 299,792,458 m/s
- but Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.
- • The city's 1920 population was 10,000 (not population was 9,996 - an official figure unlikely to be accurate at full precision)
- but The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand (unusual case in which the full-precision official population figure is helpful to readers)
- • The accident killed 337 passengers and crew, and three airport workers (likely that accurate and precise figures were determined)
- • At least 800 persons died in the ensuing mudslides (unlikely that any precise number can be accurate, even if an official figure is issued)
- or Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
- • The jury's award was $8.5 million ... (where the actual figure was $8,462,247.63) ... - reduced on appeal to $3,000,001 (one dollar in actual damages, the remainder in punitive damages)
- The number of decimal places should be consistent within a list or context (The response rates were 41.0 and 47.4 percent, respectively, not 41 and 47.4 percent), unless different precisions are actually intended.
- It may sometimes be appropriate to note the lack of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
- • A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not publish information on the uncertainty of this estimate
- Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
- • The tallest player was 6 feet 3 inches (not ... about 6 feet 3 inches - heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)
- but The witness said the assailant was about 5 feet 8 inches tall ("about" because here the precise value is unknown, with substantial uncertainty)
- The reader may be assumed to interpret large round numbers (100,000 troops) as approximations. Writing a quantity in words (one hundred thousand troops) can further emphasize its approximate nature.
Non-base-10 notations
- In computer-related articles, use the prefix
0x
for hexadecimal,0
for octal, and0b
for binary, unless there is a strong reason to use some other notation.[5] Explain these prefixes in the article's introduction or on first use. - In all other articles, use
<sub>
to create subscripts: 1379, 2013. Markup: 137<sub>9</sub>, 201<sub>3</sub> - For bases above 10, use symbols conventional for that base (e.g. for base 16 use 0–9 and A–F.
Units of measurement
Unit choice and order
Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. 200 kilometers (120 mi).
In all articles, the primary units chosen will be SI units, non-SI units officially accepted for use with the SI, or such other units as they appear in-game.
Unit names and symbols
- Definitions:
- Examples of unit names: foot, meter, kilometer.
- Examples of unit symbols: ft, m, km.
- Unit names and symbols should follow the practice of reliable sources.
- In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. Up to 15 kilograms of filler is used for a batch of 250 kg).
- Exception: Certain units are generally represented by their symbols (e.g. °C rather than degrees Celsius) even on first use, though their unit names may be used for emphasis or clarity (automatic conversion of degrees Celsius to degrees Fahrenheit).
- Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
- Units unfamiliar to general readers should be presented as a name–symbol pair on first use, linking the unit name (Energies were originally 2.3 megaelectronvolts (MeV), but were eventually 6 MeV).
- Ranges use unspaced en dash (
{{ndash}}
) if only one unit symbol is used at the end (e.g. 5.9–6.3 kg), and spaced en dash ({{snd}}
) if two symbols are used (e.g. 3 μm - 1 mm); ranges
in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (e.g. from 5.9 to 6.3 kilograms, from 5.9 kilograms to 6.3 kilograms, from 5.9 to 6.3 kg and from 5.9 kg to 6.3 kg are all acceptable).
- Length–width, length–width–height and similar dimensions may be separated by the multiplication sign (
×
or×
) or the word by.- With the multiplication sign, each number should be followed by a unit name or symbol (if appropriate):
- • 1 m × 3 m × 6 m, not 1 × 3 × 6 m, (1 × 3 × 6) m nor 1 × 3 × 6 m3
- • a metal plate 1 ft × 3 ft × 0.25 in
- • a railroad easement 10 ft × 2.5 mi
- With by, the unit need be given only once: 1 by 3 by 6 metres or 1 by 3 by 6 m
- The unspaced letter x may be used in common terms such as 4x4.
Aspect | Guideline | Acceptable | Unacceptable |
---|---|---|---|
Unit names and symbols | Unit symbols are uncapitalized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.[6] | 8 kg 100 kPa |
8 Kg 100 kpa |
Unit symbols are undotted. | 38 cm of rope | 38 cm. of rope | |
Unit names are given in lower case except: where any word would be capitalized, or where otherwise specified in the SI brochure or this Manual of Style. |
|
A Gallon equals 4 Quarts. | |
The spelling of certain unit names (some of which are listed in § Specific units, below) varies with the variety of English followed by the article. | |||
Write unit names and symbols in upright (roman) type, except where emphasizing in context. | 10 m 29 kilograms |
10 m 29 kilograms | |
Thus each two-liter jug contained only two quarts. | |||
Numeric values | Do not spell out numbers before unit symbols ... | 12 min | twelve min |
... but words or figures may be used with unit names. |
|
||
Values with no accompanying unit are usually given in figures. | Set the pointer to 5. | Set the pointer to five. | |
Use a nonbreaking space ({{nbsp}} or ) between a number and a unit symbol, ...
|
29 kg (markup: 29 kg or 29 kg )
|
29kg | |
... though with certain symbols no space is used (see "Specific units" table below) ... | 23° 47′ 22″ | 23 ° 47 ′ 22 ″ | |
... a normal space is used between a number and a unit name. | 29 kilograms (markup: 29 kilograms )
|
||
To form a value and a unit name into a compound adjective use a hyphen or hyphens ... |
|
||
... but a non-breaking space (never hyphen) separates a value and unit symbol. |
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a 10-cm blade | |
Plurals | SI unit names are pluralized by adding the appropriate -s or -es suffix ... | 1 ohm; 10 ohms | |
... except for these irregular forms. | 1 henry; 10 henries 1 hertz; 10 hertz 1 lux; 10 lux 1 siemens; 10 siemens |
10 henrys 10 hertzes 10 luxes | |
Some non-SI units have irregular plurals. | 1 foot; 10 feet | 10 foots | |
1 stratum; 10 strata (unusual) | 10 stratums | ||
Unit symbols (in any system) are identical in singular and plural. |
|
grew from 1 in to 2 ins | |
Powers | Format exponents using <sup>, not special characters. | km2 (markup: km<sup>2</sup> )
|
km² ( )
|
Or use squared or cubed (after the unit being modified). | ten metres per second squared | ten metres per squared second | |
For areas or volumes only, square or cubic may be used (before the unit being modified). | ten metres per square second | ||
tons per square mile | |||
sq or cu may be used with US customary or imperial units, but not with SI units. | 15 sq mi 3 cu ft |
15 sq km 3 cu m | |
Products | Indicate a product of unit names with either a hyphen or a space. |
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Indicate a product of unit symbols with · or
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Exception: In some topic areas such as power engineering, certain products take neither space nor · . Follow the practice of reliable sources in the article's topic area.
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To pluralize a product of unit names, pluralize only the final unit. (Unit symbols are never pluralized.) | ten foot-pounds | ten feet-pounds | |
Ratios, Rates, Densities |
Indicate a ratio of unit names with per. | meter per second | meter/second |
Indicate a ratio of unit symbols with a forward slash (/ ), followed by either a single symbol or a parenthesized product of symbols - do not use multiple slashes. Or use −1, −2, etc.
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To pluralize a ratio of unit names, pluralize only the numerator unit. (Unit symbols are never pluralized.) |
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Some of the special forms used in the imperial and US customary systems are shown here ... |
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... but only the slash or negative exponent notations are used with SI (and other metric) units. |
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gsm | |
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kph | ||
Prefixes | Prefixes should not be separated by a space or hyphen. | 25 kilopascals |
|
Prefixes are added without contraction, except as shown here: | kilohm megohm hectare |
kiloohm megaohm hectoare | |
The centi-, deci-, deca-, and hecto- prefixes should generally be avoided; exceptions include centimetre, decibel, hectolitre, hectare, and hectopascal. |
|
1 hectometre | |
Do not use M
for 103, MM for 106, or B for 109 (except as noted elsewhere on this page for M and B, e.g. for monetary values) |
3 km 8 MW 125 GeV |
3 Mm 8 MMW 125 BeV | |
Mixed units |
Mixed units are traditionally used with the imperial and US customary systems ... |
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... and in expressing time durations ... |
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... but are not normally used in SI. |
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1 m 33 cm |
Quantities of bytes and bits
In quantities of bits and bytes, the prefixes kilo- (symbol k or K), mega- (M), giga- (G), tera- (T), etc., are ambiguous. They may be based on a decimal system (like the standard SI prefixes), meaning 103, 106, 109, 1012, etc., or they may be based on a binary system, meaning 210, 220, 230, 240, etc. The binary meanings are more commonly used in relation to solid-state memory (such as RAM), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.
Follow these recommendations when using these prefixes in UniWiki articles:
- Following the SI standard, a lower-case k should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital K should be used instead to indicate the binary prefix for 1024 according to JEDEC. (If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use Ki instead).
- Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article. Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
- The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on hard drives, bit rates, and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
- Where consistency is not possible, specify wherever there is a deviation from the primary definition.
- Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
- • A 64 MB (64 × 10242-byte) video card and a 100 GB (100 × 10003-byte) hard drive
- • A 64 MB (64 × 220-byte) video card and a 100 GB (100 × 109-byte) hard drive
- • A 64 MB (67,108,864-byte) video card and a 100 GB (100,000,000,000-byte) hard drive
- Avoid inconsistent combinations such as A 64 MB (67,108,864-byte) video card and a 100 GB (100 × 10003-byte) hard drive. Footnotes, such as those seen in Power Macintosh 5500, may be used for disambiguation.
- Unless explicitly stated otherwise, one byte is eight bits (see History of "byte"').
The IEC prefixes kibi- (symbol Ki), mebi- (Mi), gibi- (Gi), etc., are generally not to be used except:[9]
- when the majority of cited sources on the article topic use IEC prefixes;
- in a direct quote using the IEC prefixes;
- when explicitly discussing the IEC prefixes; or
- in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.
Currencies and monetary values
Choice of currency
- In country-specific articles, such as Economy of Australia, use the currency of the subject country.
- In non-country-specific articles such as Wealth, use US dollars ($123), euros (€123), or pounds sterling (£123).
Currency names
- Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent but a five-dollar bill, four quarters, and one penny total six dollars one cent. Exception: where otherwise required, as at the start of a sentence or in such forms as Interstellar Kredits.
- To pluralize euro use the standard English plurals (ten euros and fifty cents), not the invariant plurals used for European Union legislation and banknotes (ten euro and fifty cent). For the adjectival form, use a hyphenated singular: (a two-euro pen and a ten-cent coin).
Currency symbols
- In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. A$52), with subsequent references using just the appropriate symbol (e.g. $88), unless this would be unclear. Exceptions:
- In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries - see [[Wikipedia:Currency symbols#dollar variants|Wikipedia:Dollar variants) use the full signifier (e.g. US$, A$) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
- In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened (€26, £22 or $34), unless this would be unclear.
- The pound sterling is represented by the £ symbol, with one horizontal bar. The double-barred ₤ symbol is ambiguous, as it has also been used for the Italian lira and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the Irish pound, IR£) use the symbol conventionally preferred for that currency.
- If there is no common English abbreviation or symbol, follow the ISO 4217 standard. See also List of circulating currencies.
Formatting
- A period (full stop,
.
) is used as the decimal point - never a comma ($6.57, not $6,57). - For the grouping of digits (e.g. £1,234,567) see § Grouping of digits, above.
- Do not place a currency symbol after the accompanying numeric figures (e.g. 123$, 123£, 123€) unless that is the normal convention for that symbol when writing in English: smaller British coins include 1p, 2p, and 5p denominations. Never use forms such as $US123 or $123 (US).
- Currency abbreviations that come before the numeric value are unspaced if they consist of a nonalphabetic symbol only, or end in a symbol (£123; €123); but spaced
if alphabetic (R 75).
- Ranges should be expressed giving the currency signifier just once: $250–300, not $250–$300.
- million and billion should be spelled out on first use, and (optionally) abbreviated M or bn (both unspaced) thereafter: She received £70 million and her son £10M; the school's share was $250–300 million, and the charity's $400–450M.
- In general, a currency symbol should be accompanied by a numeric amount e.g. not He converted his US$ to A$ but He converted his US dollars to Australian dollars or He exchanged the US$100 note for Australian dollars.
Conversions
- Conversions of less-familiar currencies may be provided in terms of more familiar currencies - such as the US dollar, euro or pound sterling - using an appropriate rate (which is often not the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid false precision (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. Since 2001 the grant has been 10,000,000 Swedish kronor ($1.4M, €1.0M, or £800k, not ($1,390,570, €971,673 or £848,646).
- For obsolete currencies, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), or a US-dollar equivalent where there is no modern equivalent.
- In some cases it may be appropriate to provide a conversion accounting for inflation or deflation over time.
Common mathematical symbols
- The Insert menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g.
÷
) shown here. - Spaces are placed to left and right when a symbol is used with two operands, but no space is used when there is one operand}}.
- Use
<var>...</var>
for variable names:<var>base</var> + <var>ht</var>
produces base + ht. - The
{{nbsp}}
template may be used to prevent awkward linebreaks.
Symbol name | Example | Markup | Comments |
---|---|---|---|
Plus / positive |
x + y | <nowiki><var>x</var> + <var>y</var></nowiki>
|
|
+y | <nowiki>+<var>y</var></nowiki>
| ||
Minus / negative |
x − y | <var>x</var> − <var>y</var>
|
Do not use hyphen (- ) or dashes (–, {{ndash}} , or —).
|
−y | −<var>y</var>
| ||
Plus-minus / minus-plus |
41.5 ± 0.3 | 41.5 ± 0.3
|
|
−(±a) = ∓a }} | −(±<var>a</var>) = ∓<var>a</var> }}
| ||
Multiplication, cross |
x × y | <var>x</var> × <var>y</var>
|
Do not use the letter x to indicate multiplication. However, an unspaced x may be used as a substitute for "by" in common terms such as 4x4. |
Division, obelus | x ÷ y | <var>x</var> ÷ <var>y</var>
|
|
Equal / equals | x = y | <var>x</var> = <var>y</var>
| |
Not equal | x ≠ y | <var>x</var> ≠ <var>y</var>
| |
Approx. equal | π ≈ 3.14 | {{tlx|pi}} ≈ 3.14
| |
Less than | x < y | <var>x</var> < <var>y</var>
| |
Less or equal | x ≤ y | <var>x</var> ≤ <var>y</var>
| |
Greater than | x > y | <var>x</var> > <var>y</var>
| |
Greater or equal | x ≥ y | <var>x</var> ≥ <var>y</var>
|
See also
- Wikipedia:Naming conventions (numbers and dates)
- Wikipedia:Date formattings
- Help:Date formatting and linking at Meta-Wiki
- Help:Displaying numbers and numeric expressions at Meta-Wiki
Notes and references
- ^ See UniWiki:Manual of Style § Commas
- ^ All-numeric yyyy-mm-dd dates might be assumed to follow the ISO 8601 standard, which mandates the Gregorian calendar. Also, technically all must be four-digit years, but the UniWiki is unlikely to ever need to format a far-future date beyond the year 9999.
- ^ These formats cannot, in general, be distinguished on sight, because there are usages in which 03-04-2007 represents March 4, and other usages in which it represents April 3. In contrast there is no common usage in which 2007-04-03 represents anything other than April 3.
- ^ The number in parentheses is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result – see NIST – Use of concise notation
- ^ The
0x
and0
prefixes, but not0b
, are borrowed from the C programming language. - ^ These definitions are consistent with all units of measure mentioned in the SI Brochure (see previous footnote) and with all units of measure catalogued in EU directive 80/181/EEC [1].
- ^ Only use this format if it is clear from the context whether this means hours and minutes (H:MM) or minutes and seconds (M:SS).
- ^ This format is used in astronomy (see the IAU Style Manual for details).
- ^ The UniWiki follows common practice regarding bytes and other data traditionally quantified using binary prefixes (e.g. mega- and kilo-, meaning 220 and 210 respectively) and their unit symbols (e.g. MB and KB) for RAM and decimal prefixes for most other uses. Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-) to distinguish the meaning of the decimal SI prefixes (e.g. mega- and kilo-, meaning 106 and 103 respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the ISO/IEC 80000, consensus on Wikipedia in computing-related contexts currently favours the retention of the more familiar but ambiguous units KB, MB, GB, TB, PB, EB, etc. over use of unambiguous IEC binary prefixes.